The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Electronic components include semiconductor dies and semiconductor packages, which generally include one or more semiconductor dies and are often referred to as “chips.” The semiconductor dies are often supported in the semiconductor packages by another electronic component in the form of a substrate or carrier such as, for example, leadframes that include a plurality of leads. The leads can be utilized to couple the semiconductor package to other electronic components or substrates such as, for example, circuit boards. Alternatively, the semiconductor packages and the semiconductor dies contained therein can be coupled to the other electronic components or substrates in a different manner such as, for example, directly with solder bumps.
In order to provide electrical inter-connections and intra-connections among and between the various electronic components, bond wires are often used. The bond wires are generally coupled to bond pads located on the electronic components. FIG. 1A is a cross sectional view of a semiconductor die 100 that includes a bond pad 102 within a passivation layer 104 on a metal layer 106. As can be seen, the bond pad 102 is exposed and the passivation layer 104 has been fully, or nearly fully, opened at the location of the bond pad 102 to expose the bond pad 102. The bond pad 102 is generally made up of a suitable type of conductive material such as, for example, aluminum. A bond wire 112 to be coupled to the bond pad 102 generally is made up of another conductive material such as, for example, copper or gold. The tip of the bond wire 102 is burned to create an end 114 to be coupled to the bond pad 102. As can be seen in FIG. 1B, the bond wire end 114 is then applied to the bond pad 102 in order to couple the bond wire 110 to the bond pad 102, thereby providing a conductive connection between the bond wire 110 and the bond pad 102. The coupling of the bond wire 112 to the bond pad 102 can be performed while the bond wire end 114 is still soft or molten from the burning that created the bond wire end 114, or through a soldering process that reheats the bond wire end 114.
When the bond wire end 114 is coupled to the bond pad 102, an inter-metallic compound (not illustrated) is formed between the bond wire end 114 and the bond pad 102 to thereby provide a bond between the bond wire end 114 and the bond pad 102. Various tests, such as, for example, reliability tests, are generally performed to test the bonding of the bond wire end 114 to the bond pad 102. Such tests can lead to contamination of the bond between the bond wire end 114 and the bond pad 102 from various irons and/or chemicals, e.g., chlorine. Such contamination can lead to problems with the integrity of the bond between the bond wire end 114 and the bond pad 102 and the inter-metallic compound formed therebetween. Problems with the integrity of the bond can include a potential failure of the bond and/or a separation of the bond wire end 114 from the bond pad 102.